I think the reason that Guardian readers are so insufferable is because they *know* they are right. If you don't agree with their right on view of thinking, you are somehow beneath them, because, as they are the most liberal, they are therefore obviously, the most enlightened.
In reality, they are often the biggest *****. Everything in the "Daily Fail" is vile, evil and wrong, and reading about how prejudiced against a black, female, homosexual, transgender, one legged, Somali woman is prejudiced against, makes us realise how evil white working class people are.
The Daily Mail makes you hate the underclass (and prejudice against other people)
The Guardian makes you pity the underclass and resent and fear the 'poorly educated' working class, for how they resent the underclass.
One invites you to dislike the minority, one invites you to dislike the majority, both are wrong.
I dislike both, but I dislike the Guardian more, purely because it preaches that its all kind, at least the Daily Mail doesn't really hide the fact its a rag.